1. Field of the Invention
The present invention relates to a technology for transmitting and receiving data in a communications system equipped with a multipath function.
2. Description of the Related Art
A communications system equipped with a multipath function in which a plurality of paths for data transmission/reception are provided between communication apparatuses has come into practical use. For example, the multipath method and the multilink Ethernet method are known for realizing the multipath function.
The multipath method realizes the multilink by using a plurality of Network Interface Cards (hereinafter referred to as NICs), making the transmission paths between NICs and a switching hub redundant and using a NIC exclusively, thereby realizing the multilink.
The multilink Ethernet method realizes the multilink by using a plurality of Ethernet (registered trademark) cards and connects the cards to a switch having a multilink Ethernet function, making transmission paths between the NICs and the switch redundant and using the NICs simultaneously. The multilink Ethernet method specifically includes MAC address distribution method, round-robin distribution method, destination IP address distribution method, source/destination IP address distribution method and so on.
In the multilink method, the order in which the receiving apparatus receives packets is not assured. In this regard, techniques has been proposed (for example, in Patent Document 1), for distinguishing a packed that has not arrived from a lost packet on the receiving apparatus side of the multilink communications system.
[Patent Document 1]
    Japanese Patent Application Publication No. 2004-80139